Multimode interference (MMI)-based optical splitter is designed and experimentally demonstrated on silicon on insulator for on-chip optical interconnect. We have proposed MMI-based 1 × 2 optical 3-dB splitter having a compact footprint (2.8 × 27 μm2). The device shows low excess loss of 0.05 dB for TE mode at operating wavelength 1550 nm and <0.45 dB over broad wavelength 1430 to 1675 nm (S–C–L–U band) using eigenmode expansion (EME) method. The proposed MMI-based Mach–Zehnder interferometer structure is implemented for arbitrary power splitting applications having excess loss <1 dB for wavelength range 1520 to 1580 nm. Moreover, the fabrication tolerance of the device is analyzed using the EME method. The proposed device can be used for on-chip optical interconnects in photonic integrated circuits.
A high extinction ratio polarization beam splitter (PBS) based on cascaded multimode interference couplers is designed on silicon on insulator substrate using 3D beam propagation method (BPM). The numerical simulation tool shows that the polarization extinction ratio is greater than 20 dB for both TE and TM polarizations over C-band wavelength range. The proposed device has insertion loss below 0.8 dB at wavelength 1550 nm for TE and TM polarization. The polarization beam splitter has a compact size and relaxed fabrication tolerance in term of width and length of MMI coupler. These parameters make it as a promising element for polarization diversity circuit and photonic integrated circuits.